Direct binding of the verprolin-homology domain in N-WASP to actin is essential for cytoskeletal reorganization.
Verprolin is a yeast protein whose inactivation leads to a cytoskeletal defect characterized by the abnormal organization of actin filaments. Recently, two mammalian proteins previously shown to regulate the actin cytoskeleton, Wiskott-Aldrich Syndrome Protein (WASP) and its homolog expressed in neurons (N-WASP), were found to possess short peptide motifs homologous to one part of verprolin. However, the physiological function of the homologous regions (verprolin-homology domain, VPH domain) remains unknown. Here we report the importance of the VPH domain as the direct actin binding region. In the case of N-WASP, the VPH domain co-acts with the cofilinhomologous region to sever actin filaments in vitro. Furthermore, the VPH domain is indispensable for the reorganization of the actin cytoskeleton by N-WASP downstream of tyrosine kinases in living cells. All data demonstrate that the VPH domain plays critical roles in the regulation of the actin cytoskeleton.
Miki
H
H
Department of Biochemistry, University of Tokyo, Japan.
Takenawa
T
T
D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D003599:Cytoskeleton / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics*; D008840:Microfilament Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014923:Wiskott-Aldrich Syndrome / Q000235:genetics / Q000378:metabolism; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal
D000199:Actins; D005656:Fungal Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C090350:VRP1 protein, S cerevisiae; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal